1. Related Applications
The present application claims priority to Japanese Patent Application Number 2005-297043, filed Oct. 11, 2005, the entirety of which is hereby incorporated by reference.
2. Field of the Invention
The present invention relates to a map moving apparatus capable of automatically moving a map screen display region along a particular display polygon by using a simple operation of a user.
3. Description of the Related Art
In recent years, installing a navigation apparatus in a vehicle has become widely known. A regular navigation apparatus to be installed in a vehicle or the like includes a map/information storage medium such as a CD-ROM, a DVD-ROM or a hard disk, which stores map data for drawing a map and facility data for searching a facility or the like; a data retrieval device that retrieves the data from the map/information storage medium; a monitor that displays a map or the like; and a vehicle position detecting device that detects the current position and the orientation of an advancing direction of a vehicle by using an autonomous navigation apparatus, which uses a GPS receiver, a travel distance sensor, a gyroscope and the like, in which the navigation apparatus retrieves map data covering the current position of the vehicle from the map/information storage medium, draws a map image of an area around the vehicle position on a monitor screen based on the map data, displays a vehicle position mark at the center or a particular position of the monitor screen, moves the map image in response to the movement of the vehicle or moves the vehicle position mark while the map image is fixed on the screen, and allows a user to recognize the current position of the vehicle at a glance.
The map data stored in the map/information storage medium such as the CD-ROM, the DVD-ROM or the hard disk is sectioned into a longitude width and a latitude width of a proper size according to various scale levels, and polygons such as a road displayed on a map are stored as a coordinate set of nodes that are expressed by longitude and latitude. Further, the map data includes a road layer made up of a road list, a node table or the like, a background layer made up of polygon data for displaying roads, buildings, facilities, parks, rivers and the like on the map screen, character data for displaying characters, map signs and the like such as an administrative district name of a city, town and village, a road name, an intersection name, a facility name, and the like.
The road list and the node table are organized by a certain unit region (parcel or mesh). Nodes included in the node table are information of points, and they consist of information identifying the positions of points and the types of points such as highway junctions and road intersections. Road links included in the road list constitute information describing roads, and they consist of the starting point and the ending point of a road, and the length/attributes of the road. Generally, the starting point and the ending point of a road link are expressed as nodes, and the attributes include the type and the width of the road such as a highway and an open road. The navigation apparatus is capable of displaying maps from a wide range to a narrow range in various scales by using the above-described map data, but it cannot display detailed information when displaying a wide range (small scale), and it becomes difficult to grasp the entire image, that is, a positional relationship with surrounding areas when displaying a narrow range (large scale) due to the characteristics of the map database and navigation apparatus, so that a user arbitrarily selects a scale considered to be most appropriate, to display a map on the map screen.
Further, a typical navigation apparatus includes a route guiding function to allow a user to easily travel on a road toward a desired destination without making a mistake. According to the route guiding function, a destination can be set by various means, and the navigation apparatus calculates an appropriate route from an origin to a destination from possible routes connecting the points by taking into consideration various conditions, such as types of roads to be used, travel distance, travel time and tolls, to which the user wants to place priority, and presents it to the user. Further, the navigation apparatus stores a route that the user selects as a guiding route, displays the guiding route on the map image with a bold line in a different color from other roads while traveling, displays an intersection at which a direction on the guiding route should be changed in an enlarged state when the vehicle approaches the intersection within a certain distance, and draws an arrow or the like indicating a direction change to display it on the screen or guides the vehicle for a right/left turn by voice, and thus can guide the user to the destination. A technique in which a map is automatically scrolled along a route that was previously set to perform display from an origin to a destination is disclosed in Japanese Patent Laid-Open No. 07-55482 publication. However, in this technique, since a map screen display region is moved along a route, it is impossible to provide the user with information regarding points that do not exist near the route.
In such a navigation apparatus, when the user tries to find restaurants along the road on which the user is traveling, for example, it is possible to check the presence of restaurants along the road because the user can see the area near the particular road currently displayed on the map screen. However, if no restaurant exists along the road on the map currently displayed on the screen, the user needs to move the map screen display region along the road to find restaurants along the road.
When changing a display region of the map in the conventional navigation apparatus, the user specified a direction of moving the screen by using a touch panel function on the display screen or an input device such as a scroll key on a remote controller to move the screen away from a currently displayed screen region along the particular road, and searched for restaurants along the road or near the road, so that a problem arose that the operation became troublesome to the user.
Furthermore, in the case where the user will travel around a lake and wants to know the presence of a road closure that exists on the road around the lake or the positions of facilities such as shops and restaurants around the lake, if only a part of the lake is displayed on the current display screen, the user searches the road closure, shops and restaurants around the lake on the map while moving the map screen display region along the lake by the above-described manual operation, so that a problem existed of reducing safety during traveling.
As described above, in a map screen display device such as the conventional navigation apparatus, when a user tries to check the state of an arbitrary road ahead or the state of a road around a lake or a park, the user checks the road state and the type or the position of a facility nearby by moving the display screen region of map such that a road or a point that the user wants to refer to is displayed on a screen. Further, in the case of checking the presence of a road around a mountain, river or coast, or searching for a tourist facility around it while traveling, the user obtains the information from a map as the user moves the map along the mountain, river or coast.
When the user wanted to obtain information around a certain target such as a road, river or coast, for example, the user continuously operated the navigation apparatus until the required information was obtained, and this caused a problem of not only applying a burden to the user but also interrupting safe driving when the user is driving a car. In addition to the map screen display device such as the navigation apparatus, the same burden applies to the case of displaying a map on a personal computer and moving the screen display region of the map, for example.